Logarithmic calculator



May 29, 1926. 1,671,616

E. A. SPERRY LOGARITHMI C CALCULATOR Filed Jan'. 26. 1922 Y @mmv S31/wanton 66 67 29' 38 4s I 2Min/$52566@ m... my w {kof/vw 16mm @m1111611 1215 if f Patented May 29, 1928.

PATENT OFFICE.

y ELKER A. 'SPERRY, 0F BROOKLYN, NEW YORK.

LOGARITHMIC, CALCULATOl.

Application iled January 23, 1922. Serial No. 531,297.

This invention relates to logarithmic calculators, and more specifically tothat type of calculating instruments in which a circular or spiraly logarithmic scale is carried by a dial arranged beneath a radial pointer; the apparatus being mounted in a case similar to al Watch case and being` actuated by the usual watch Winding stem.

Suchr a calculator is shown in my U. S. Patent N o. 773., 235, dated October 25,1904. Instruments of this nature heretofore manufactured, while extremely more han-dy and more convenient to carry than lordinary slide rules, have been comparatively large and heavy, as well as costly to manufacture.'

The object of the-present invention is to improve upon the mechanism contained in the calculator, .so thatthe ydevice may be madey very much thinner .and lighter than is now the practice and regarded as necessary to obtain the desired results, and also to reduce the cost lof manufacture.

Referring to the drawings wherein Iha've shown Awhat I now consider to be the preferred form of my invention:

Fig. 1 is a vsectional side elevation taken substantially on line V1-1 of Fig. 2.

Fig. 2 is a plan view, partly vin section and with the top dial removed.

Fig. 3 is a sectional detail taken on line 3-'3 of Fig. 2V of astop member against which the spring which lholds the actuating parts in normal position rests.

Fig.4 is a sectional detail taken on line 4`4 of Fig. 2, showing means for shifting the position of the actuating mechanism.

Fig.. 5 is a yfragmentary sectional view showing amodified form of connection be tween the. operating stem and gearing.

In the drawings the case 1 is shownas comprisinga circumferential member 2 toy which are attached the bezel rings 3, 4, carrying the ycrystals 5, 6. Integral with member 2 'is shown a plat-e 7. This plate and membermaybe machined from a single dscor they'may .be cast as one piece. In short, the structure comprises a disc 7 havinga .rim 2 extendedor offset on one side.

.The central lportion of plate 7 may be thicker than the other portions or offset on the. samek side as rim 2, to form the bearing for a central rotatable shaft or spindle 9.

The core of this spindle may be bored out as indicated at l0 so as to reduce its weight.

Integral with spindle 9 I have shown a wide circumferential flange 11 which serves to bear against the central portion 8 and at the same time carries at its periphery, bevel gear teeth 12.

A thin indicating dial 13 may be carried by a reinforcing or hublike member 14 which may in turn rest upon the flange 1l, being held in .osition by a member 15 screwed upon tie spindle 9 and leaching over the said member 14 at 16. .The dial 13 is, of course, adapted to rotate independently of spindle '9. The opposite dial' 13 is shown as mounted vena similar reinforcing' hub member 14" which bears on one side against thev central portion y8 of plate 7. and is held in position by a member 1.5 screwed upon the spindle '9 and reaching over the member 14? at 16. The member 15"'thus servesl also to holdthespindle 0 in place.

Pointers 17, 18may be secured tothe opposite ends of spindle 9 by pins or screws 19 and are adapted to cooperate with the dials 13 and 13, respectively.

The back or inner surfaces of the dials 13, 13' maybe provided with circumferential bevel gearing 20, V20". As shown, this gearing may be cut in a .separate annular member 21 secured to the dial. As shown at 7', the plate '7 may be grooved or arched to provide space for the gearing 20.

The usual watch windingstem 22 is shown as reaching into the case through a sleeve 23 liXed in the case and held against longitudinal movement by a flange 24 and a collar 25. An annular groove 26 may be provided in the stem to receive the end .of a screw 27 yin sleeve 23 to prevent endwise movement of the stem. A shaft 28 bearing at one end in the thick portion 8 of plate 7 and at the other in theslee-ve 23 maybe provided with a square shank `29 reaching into a square hole inthe stem 22 so that rotation of the stem will cause rotation of said shaft. As more clearly shown in Fig. 2, an opening 30 is cut in the member 2 including plate 7 for the insertion of sleeve 23 and the shaft 28 and the other elements .associated therewith. The shaft is also adapted to endwise movement and has thereon a double-faced bevel gear or pinion 29", one side of which, when in the position shown, meshes 'with gearing 20,20', so that rotation of the stem 22 will cause the dials 13, 13 to rotate. When the dials will permit. t

the instrumentmay be made comp'arativelyA tion.

, position.

drawing, the other side of the double bevel pinion will engage gearing 12'forI actuation of the pointers 17, 18. The ratios-between the driving pinion 29 and the driven gear-V ing 20, 2Or and 12, are preferably low. Also the pinion is adapted to occupy substantially all of the distance between tlie'dials. In` other words, they dials are placed asclose `togetlieras the pinion and the gearing on the With this construction,

thin. Also with the arrangement shown, i; e., with the pinion actuating the oppositely disposed dials, thedia-ls willbecdriven in opposite directions. On the other hand, Iit will be seen that the pointers 17, 18 will be driven in thesame direction. Said pinion may be normally held in one of' its positions and adaptedto be shifted to the other posiplate 47. .This stop -may lit tightly in the slots and may ,have bent over portions 33 resting against plate 7 to` aid in fixing it-iii A hole" may be provided in the stop 31 for thev shaft 28 yto pass through as shown, and to move freely vtherein. Fixed on the shaft is shown a collar 34.` A` spring 35 may befprovided on the shaft, pressingi against stop31 and collar 34.` This vwill hold the'bevel pinion 29 normally inmeshv with gearing 2O and 20.

For moving the pinion into engagement with gearing 12, I may employ a lever 36,

- (see also Fig. 4) provided with an enlarged section 37 vhaving a slot 38 adapted to tit over fshaft'f'28'and bear against the bevel pinion asv a shoulder.- The central or en-v larged portion of lever 36 mayV project into the opening 30, 'while the 'armsofthe lever' rest upon the plate 7. Said lever maybe curvedas shown in Fig. 2 to conform to the curvature of the case 1. Reaehinginto vthe case in openings 39, 40 eut in member 2 and plate7c are shownrods 41, 42 provided on their outer ends with buttons 43, 44 and resting at their inner ends45, 46 against lever 36.

Springs 47 secured to member 2 and passing' through rods 41 may .be provided to pressV therods` outwardly in. the rposition shown,v

pins 48 being provided in therods to engage member 2 to, limit the outward movement of the'rods. It will be seen that if` one of' the rodsv 41,-42 `is pressed inwardly against lever 36, theother rod will act as a 'fulcruni and the bevel vvpinion will be moved by the lever intov mesh with gearing 12. j v e Instead of` shifting they gears by means of rods 41, 42, Imay do this `by means of the stem 22. For this Vpurpose I have shown the stein as connected by a pin 49 (Fig. 5)' to the shaft 28; `the pinengaging the shaft loosely in a slot 28 to permit lost motion axially (longitudinally of shaftf28) between To this end I have shown a stop 31 (see also Fig. 3) inserted in slots 32 in thethe stem and the shaft, or any suitable y resilient connection may be employed which will yield to axial strain so that shaft 28 may be moved inwardly by stems 43-44 withoiitmoving stem 22. In the position .shown in Fig. 5 the stein and shaft are' pushed in, in which case the pinion 29 will engage gearing 12.

The spring 3 5 acting f against collar '34 will as heretofore stated,

return the parts to normal position when the stem 22 is released. In this form the screw 27 is shown as proyecting into a groove 26 adapted to permit the necessary end play` of thestem 2,2 but rotates therewith.y l'

In order that the dials may not be moved 'se when the pointers are being actuated yand,l vice versa, and to prevent movement of these parts in general, I may employ brakingf-` f means therefor. Such means may comprise a resilient arm v50 securedat one end by screws 51 to plate 7 and carrying at its other end a vfriction shoe 52 adapted to press against the rear` surfaceof dial 13. means 53' m ay be provided for braking dial 13. In connection with the pointers, I mayv provide a hole 54 in the portion 8 ofplate 7 reaching in adjacent to the spindle 9. A corlror other friction member 55 maybe inserted in said hole and pressed by .a spring 56 against the spindle; the spring in turn resting against a screw plug 57 secured lin the hole 54.

Similar,

If desired, one Aor more rollers may be employed to aid in steadying the dials and to revent anv tendenc to war O eninvs,

59 may be provided in the Vplate 7 so that the rollers may reach through' and engage both dials. The rollers may rotate on an axle 60 carried by a member 61 securedlto plate 7.

llVhile the Vdial r faces and the graduations' thereon are not shown here, it willbeundeistood that any suitablescale may be ein-r' ployed. Thus, the scales shown in my afore said Patent, No. 773,235 maybe employed if desired, or the usual slide rule scales may be used. y t

,n For the fixed reference, I have shown av hairV line 62 which'may be. cut into the crystals 5 and (i. y a pointer may be employed instead. 1 Such a pointer while not shown here cou ld,"of

course, be secured to member 2 and project` inwardly therefrom.

In accordance with the provisions of thek patent statutes, I'have herein described the p by other means. Also, while itis designed? to use' the various features and elements in Or, obviously, if desired,

the combination and relations described,

some, of these `may be altered and othersomitted without interfering with the more general results outlined, and the invention extends to such use.

Having herein described my invention, what I claim and desire to secure by Letters Patent is:

1. In a calculating device, a double faced casing, a supporting element carried by said casing, a member rotatably carried by said element, said member being centrally disposed With respect to the casing, an index carried by said member adjacent each of said faces, a movabledial also disposed adjacent each of said faces, and a single means for actuating said dials and said member.

2. In a calculator, a double faced casing, a supporting member in' said casing, a spindle rotatably carried by said member, gearing associated with said spindle, a pointer adjacent each of said faces, carried by said spindle, a dial rotatably mounted adjacent each of said faces back of said pointers, gearing on the inner side of each of said dials, a single pinion movable into engagement with said first named gearing and said second named gearing and means for actuating said pinion.

3. In combination with a` double faced watch casing having the usual winding stem, a reference dial rotatably mounted adjacent each of said faces, an index pointer mounted over each of said dials, bevel gearing on the inner surface of each of said dials, an additional bevel gear between said dials connected with said pointers, a bevel pinion positioned between said dials and rotatably connected to said stem and means for moving said pinion into engagement with said first mentioned gearing vin one position and said second mentioned gearing in another position.

4. Incombination with a double faced watch casing having the usual winding stem, a reference dial rotatably mounted adjacent each of said faces, a spindle passing through both of said dials, a pointer positioned over each of said dials and carried by said spindle, `bevel gearing on the inner surface of each of said dials, bevel gearing on said spindle, a bevel pinion between said dials and connected to said stem, said pinion being adapted to engage said first mentioned gearing in one position and said second mentioned gearing in another position, means resiliently pressing said pinion toward one of said positions and manually operable means for moving the same intol the other position.

5. In a-calculator, a pair of oppositely disposed indicator dials, means projected between said dials and adapted `to operatively connect therewith and rollers engaging the inner surfaces of said dials.

6. In a double faced calculator, a rotating dial on each face, a pointer cooperatingk with each dial, gearing between said dials connected with the dials and pointers, a bevel pinion between said dials, a radial slidable shaft carrying said gea-r adapted to actuate said gear andv to shift its relationship with said gearing.

7. In a calculator, a disc having a rim and a hub offset on one side thereof, a bezel ring carried by said rim, a spindle operating in said hub, a pointer carried by said spindle, a dial rotatably mounted with respect to said spindle and hub, and means for actuating said pointer and dial.

8. In a calculator, a disc having a rim and a hub offset on one side thereof, a bezel ring carried by said rim, a spindle operating in said hub, a pointer carried by said spindle, a. dial rotatably mounted with respect to said spindle yand hub, gearing connected with said dial, gearing connected with said pointer, a radially extending shaft, a bevel pinion carried thereby, a

bracket supported by said disc, a sprlng connected with said shaft and engaging said bracket and adapted to hold said pinion in mesh with one of said gearings and manual means for shifting said pinion into mesh with said other gearing.

9. In a calculator, a double faced casing, a dial adjacent each face, gearing on the inner face of each dial, a pinion between said dials adapted to engage said gearing, means without said casing having a lost motion connection with said pinion for operating the same.

l0. In a calculator, a pair of oppositely disposed indicator dials, a spindle reaching through said dials, a pointer positioned over each dial and secured to said spindle, and an actuating element for selectively operating said dials and pointers.

In testimony whereof I have affixed my signature.

ELMER A. SPERRY.

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